Electronic apparatuses (computers, cell phones, navigation systems, etc.) currently on the market include various electronic systems (computational logic, non-volatile memories, sensors, input/output interfaces etc.). In general, such electronic systems use operating voltages that vary considerably one from another. However, the electronic apparatus usually receives one supply voltage (typically provided by the power grid or by batteries). Consequently, the electronic apparatus includes an internal voltage regulator that is input with the supply voltage and outputs a regulated voltage adapted to supply some electronic systems (such as the computational logic), and a voltage multiplier (e.g., a charge pump) that is input with the regulated voltage and outputs a boosted voltage, higher in absolute value, and adapted to supply other electronic systems (such as the non-volatile memories).
Voltage converters often face the following drawbacks. The electronic systems connected to the charge pump absorb current in a discontinuous manner over time. Very often, such current absorption is characterized by absorption peaks, as it occurs in non-volatile memories during data writing. This may cause a sudden drop in the regulated voltage, with a negative effect on the performance of such electronic systems, possibly up to a malfunction thereof.
A known technique to overcome such drawbacks is to implement a feedback loop on the voltage converter through an operational amplifier having a very high response speed (for responding with enough speed to the power consumption peaks). However, this operational amplifier has very high power consumption.
Another known technique includes adding a stabilizing capacitor to the output terminal of the voltage regulator, so as to respond to the power consumption peaks through an electric charge stored therein. However, this technique involves a considerable amount of area consumption for implementing the stabilizing capacitor and electric power for maintaining it charged.
Another drawback is that the regulated voltage usually has a very low value (for correctly powering the corresponding electronic systems). Therefore, the charge pump has a rather bulky structure (e.g., with a large number of pumping stages) for obtaining the desired boosted voltage (very high) from the regulated voltage.